Size: About half of the Earth; 6,779 km in diameter
Weight: Lighter than Earth, but still 640,000,000,000,000,000,000,000kg in weight!
Temperature: Generally colder than the Earth; -50 to -60 degrees Celsius
Density: Heavier than water, 3.9 g/cm3
Composition: Rocks and metals
Satellite: Phobos and Deimos
Recent exploration missions: Insight by NASA (2018-); HOPE by UAE (2021-); Tianwen-1 by CNAS (2021-); Perseverance by NASA (2021-)
Something curious about Mars
1. Are there aliens on Mars?
Nobody has found any life on Mars yet. Remember that living things need water and heat to survive, just as we drink water and eat food to keep our bodies warm. But on Mars, a frozen body with cold weather, is a very difficult place for beings to live in. However, creatures might have existed on Mars about 3~4 billion years ago. Mars used to be warmer than Mars today because it had a lot of carbon dioxide, which is very good at heating things up, and it had active volcanoes. It is also said there were even rivers and oceans.
2: Mars and its own two moons
Mars was formed 4.6 billion years ago, almost the same as our Sun. The surface of Mars today is largely different from when it was made. Mars became a bumpy planet with numerous volcanoes, rivers, faults, and craters formed by the impacts of astronomical objects. Did you know it also has two lumpy moons called Phobos and Deimos orbiting around it? We still do not know when Phobos and Deimos were formed, but we know that Phobos is getting closer to Mars little by little, so it will either hit Mars or disappear into pieces in the end. On the other hand, Deimos is slowly moving away from Mars, so in the future.
3. Are humans able to live on Mars?
Wherever we go on Mars, the temperature is somewhere between -87℃ and -5℃. That’s about as cold as the south pole of the Earth, so people may be able to live on Mars in some ways. Although the atmosphere of Mars is about 1/150th thinner than Earth’s, its large portion is carbon dioxide, which has a greenhouse effect. So if we can collect it, we could be able to warm this planet. In addition, there’s ice in the soil of Mars, so if we heat it up, we can make some water. But some of the ice contains poisonous things for us, so we’ll need a water purifier. As you might already know, carbon dioxide, water, sunlight, and soil are all that’s needed to grow plants, so we’d better bring some vegetable and fruit seeds with us.
Checklist
- Humans can live there (Yes or No): Yes but maybe not yet
- Humans can breathe there (Yes or No): No, very thin atmosphere
- Humans can walk on the surface there (Yes or No): Yes, seemingly a terrestrial desert area
- The temperature of its surface is (Hot or Cold): Cold, colder than the south polar region on the Earth
- It is a (sinking or floating) object: Sinking, like the Earth
- Water exists there (Yes or No): Yes and no; Lots of ice, though. Liquid water may exist but very rare